1. Field of the Invention
This invention relates to novel saponins which can be isolated from "AMACHAZURU" in Japanese, Gynostemma pentaphyllum Makino belonging to Cucurbitaceae, their use and a method for preparing the same.
2. Description of the Prior Art
It is known that some plants such as Panax ginseng and the like contain saponins. Nagai et al report that Gynostemma pentaphyllum contains a saponin, whose acid hydrolysis gives panaxadiol as a sapogenin [cf. The 23rd Meeting (1976) of Pharmacognosy Society in Japan]. Also, M. Takemoto et al present that an enzymatic hydrolysis of a saponin extracted from the above plant gives Compound K which is a prosapogenin of a saponin isolated from Panax ginseng [cf. The 24th Meeting (1977) of Pharmacognosy Society in Japan].
The inventors of the present invention have isolated a mixture of saponins in substantially pure form as well as a group of new saponins in individual form, from Gynostemma pentaphyllum, and also have found that the saponins possess unique pharmacological activities.